Air conditioning apparatus



Jan. 26, 1943. R. R. CANDOR ,3 9,

A AIR CONDITIONING APPARATUS,

Filed July 24, '19s"! 2 Sheets-Sheet 1 V m it; /LZ' zz 24: f T

I72 5 1'0 :24 a i INVENTOR3 a1 WMQ-WKM ATTORNEYS.

Jan. 26, 1943. R. R. CANDOR 2,309,155

AIR CONDITIONING APPARATUS 1 Filed July 24, 1937 2 Sheets-Sheet 2 I W Q-NINVEN'TORST A W Q-J ATTORNEYS Patented Jan. 26, 1943 UNITED STATES PATENT OFFICE AIR CONDITIONING APPARATUS.

Robert R. Candor,

eral Motors Corporatio poration of Delaware Application July 2 4, 1937, Serial No. 155,534

6 Claims.

This invention relates to refrigerating apparatus and more particularly to a refrigerating apparatus which may also purposes.

- It is an object of this invention to provide a method and an apparatus for maintaining the temperature of a stant irrespective mosphere.

given space substantially conof the temperature of the at- Another object of this invention is to provide be used for heating Dayton, Ohio, assignor to;Genin, Dayton, Ohio, a corcondenser 24. The condenser 24 provided with a cooling-jacket 26. Water issupplied to the" cooling jacket 26 through pipe 28 and is discharged through the outlet 30. The amount of water supplied to the condenser is regulated by the valve 32 which is controlled in. response to pressure within the pipe line which conveys the compressed refrigerant to the condenser.

When the apparatus is set for cooling, compressed refrigerant leaves the compressor via the pip 36 which leads to the three-way valve 38. This valve is set so as to discharge the compressed refrigerant into pipe 40 which leads to the three-way valve 42 which in turn is set to discharge into the pipe 34 leading to the con- 1 denser. The liquid refrigerant leaves the convide means for dehumidifying the air when'the humidity becomes too high even though the effective temperature is comfortable, and to prowide means for adding moisture to the air when ;he humidity becomes too low.

Further objects and advantages of the present nvention will be apparent from the following de- :cription, reference being had to the accompanyng drawings, wherein a preferred form of the iresent invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic showing of my air onditioning apparatus with the valve set for ooling; p I i Fig. 2 is a diagrammatic view 'of the same aparatus shown in Fig.- 1 with the valve set for eating;

Fig. 3 is a diagrammatic view showing the conr01 mechanism which may be used for changing ver from heating to cooling and vice versa;

Fig. 4 is a diagrammatic view showing the elecrical circuit which may be used in my system.

Referring now to Fig. l of the drawings, I we shown an enclosure It provided with my inditioning apparatus. In this figure the apiratus is shown set for cooling the room during 1e summer season. A'heat exchange unit [2 is ounted within the conditioning chamber l4 and provided with an inlet l6 and an outlet I 8. :1 internal combustion engine 20 is provided for 'iving the compressor 22. The compressor dislarges compressed refrigerant into a receiver denser 24 via the pipe 44 which leads to the three-way valve 45. The three-way valve 45 is set to discharge into the pipe 46 which. leads to the three-way valve 48. The three-way valve 48 being set $025 to discharge into the'pipe line It leading to the heat exchange coil I2. The valve 50 placed in line It is a thermostatic expansion valve which automatically opens to admit additional refrigerant into the heat exchange coil l2 when the pressure within the coil l2 falls below a predetermined amount. This expansion valve is provided with a thermostatic means 5| which v automatically throttles the valve when the refrigeration effect reaches the return line l8.

Whenever the system is used for cooling purposes the refrigerant is required to pass through the thermostatic expansion valve 50. A by-pass line 52 is provided around the thermostatic expansion valve 50. This by-pass is provided with a solenoid valve 54 which automatically opens when changing over from summer to winter operating conditions. The return line l8 leads to a three-way valve 56 which is set to discharge into the pipe line 58 leading to the three-way valve 60 which, during summer conditions, is set to deliver the refrigerant vapor into the line 62 leading to the lntakeof the compressor.

In order to dissipate the heat generated by the internal combustion engine and the compressor, a water jacket 64 has been provided around the internal combustion engin and a water Jacket 66 has been provided around the compressor 22.

Cooling water is supplied to the Jackets 64 and 66 through the pipe line 88. The heated water leaves the jackets 84 and 66 through the pipe l0 which leads to the three-way valve 12. Threeway valve 12 may be set as'shown in Fig. -1 to convey the water into pipe-I4 which is connect ed with pipe 16 leading to a water tan]; 1! which is provided with a discharge pipe 80 through which the water is finally discharged from the system. The three-way valve I2, as will be explained hereinaftenmay beset so as to convey the hot water coming through the pipe I through a heating coil 82. located in the conditioning chamber I4.

A fan 84 is provided for circulating air through the conditioning compartment I4. The compartment [4, it will be noted is provided with a partition member 86 which divides the conditioning chamber into two separate passages. Butterfly dampers 88,- 89, and 90 are provided for controlling the flow of air through the conditioning compartment. As shown in Fig. 1, the damper 88 is set so as to cause all of the air flowing through the apparatus to flow over the heat exchange coil I2, and the dampers 89 and 90 are set so as to cause all of the air to also flow over the coil 82 which may or may not reheat the air depending upon the'setting of the valve 12 as will be explained hereinafter. The exhaust from the internal combustion engine is caused to pass through the exhaust pipe 92 into the exhaust tank 94 which is provided with a mufiled outlet 96.

Whenever it is desired to cool air for the com- I partment I0, the internal combustion engine is caused to operate thereby compressing the refrigerant by meansof the compressor 22 which discharges the compressed refrigerant into the condenser 24.. The refrigerant is condensed in the condenser 24 and is forced upwardly through the pipes 44, 46, and I6 into the heat exchange coil I2 which under these conditions acts as an evaporator cooling coil to cool the air circulated over the coil by means of the fan 84. The evaporated refrigerant leaving the coil I2 is conveyed through the pipes I8, 58, and 62 back to the compressor.

The air passing over the cooling coil I2 will deposit a certain amount of moisture on the coil I2 with the result that the air leaving the apparatus will have its relative humidity lowered. Whenever it is desirable to lower the humidity without lowering the temperature of the air, "the threeway valve 12 may be set so as to convey the hot water leaving the cooling jackets 64 and 66 through the heating coil 82 with the result that the air passing through the conditioning chamber I4 will be reheated an appreciable amount. All of the three-way valves and the butterfly valve may be manually controlled'so as to change over from cooling in the summertime to heating in the wintertime or, as will be explained hereinafter,

automatic means may be provided for changing over from cooling to heating. The three-way valve I2 may be manually controlled or it may be controlled automatically in a manner to be explained hereinafter. When it is desired to change over from cooling in the summertime to heating in the winter, the valves 38, 42, 45, 48, 56, 60, and 12 are all adjusted to the position shown in Fig. 2. The butterfly valves are all adjusted to the position shown in Fig. 2 so that theair flowing through the conditioning apparatus flows over the coils I2 and 82 in parallel. In the case of manual adjustment, the butterfly valves may,

of course, be set so as to cause the air to flow over' only one of the coils or to flow over both of the coils in series as shown in Fig. 1.

With the apparatus functioning as a heating system, the supply of water for the receiver 24 is shut off and the refrigerant -.leaving the compressor flows through the pipe 36; valve 38; pipe 98; valve 48; pipe I6; by-pass pipe 52; valve 54; heat exchange coil I2, which under these conditions acts as a condenser for the refrigerant; pipe I8; valve 56; pipe I00; valve 42; pipe 34; receiver 24; pipe 44; valve 45; pipe I02; expansion valve I04; coil I06, which under these conditions acts as an evaporator; coil I08, which also serves to evaporate the refrigerant; pipe IIO; valve 60; and, finally, pipe 62, which returns the vaporized refrigerant to the compressor 22. With this arrangement the cycle has been reversed, and the heat exchange coil I2, in place of serving 'as an evaporator, serves as a condenser with the result that air flowing over the coil is heated and the condensed refrigerant is evaporated in the coils I06 and I08.

A considerable amount of heat is dissipated by the internal combustion engine and the compressor; so, in order to utilize this heat, I have provided means for dissipating this heat into the air for the enclosure I0. Water is supplied through the feed lines 68 to the water jackets 64 and 66 of the internal combustion engine and compressor respectively, and the heated water leaving the jackets 64 and 68 is caused to circulate through the pipe 10; valve I2; heating coil 82; hot water tank I8,,where it serves to give up heat to the evaporator coil I06 before being discharged through the outlet 80. In order to utilize the heat ordinarily lost in the hot exhaust from the engine, I place the one section of evaporator coil I08 in an exhaust tank 94 so that the hot exhaust gases may be used in evaporating refrigerant with the result that the heat dissipated by the internal combustion engine is fully utilized in heating the air for the enclosure. A throttling valve I I2 is placed in the inlet 68 and is provided with a thermostatic bulb II4 placed adjacent the outlet pipe so as to control the flow of cooling fluid through the system. In this manner only the necessary amount of cooling fluid is permitted to flow through the cooling jackets.

During the winter season it may be necessary to add moisture to the air for the room and, with this in mind, I have provided a spray head II6 for spraying water over the heat exchange coil I 2 whenever humidity conditions within the enclosure require the addition of moisture to the air.

As explained hereinabove, all of the control valves may be manually operated so as to change from heating-to cooling or vice versa. However, in a system of this type it is necessary that the large majority of the valves all be shifted at the same time or, nearly. at the same time so as to provide the proper flow lines for the refrigerant. I have provided automatic means, as shown in Fig. 3, for changing the settings of various valves whenever conditions within the room necessitate the change from heating to cooling or vice versa. I have also provided a novel control system for starting and stopping the internal combustion engine and controlling the capacity of the system in response to changes in conditioning requirements.

is no longer required, and it becomes desirable to cool air for the enclosure, the niovable contact I20 will move over into engagement with the sta I66 has cammed the contact tionary contact I24. When this takes place current will flow from the main line I26 through the contact I26 and I24 through the line I26, stationary contact I66, movable'contact I62, line I64, solenoid I66, tothe main line I66. i,

Energization of the solenoid I66 causes the armature I46 to be moved to the left. Movement of the armature I46 to the left causes the contact arm I42 to engage the contact I44. It will be noted that thecontact I42 is biased into engagement with the contact I44 by means of the spring I46 and that the armature I46 is biased to the right by means of a spring I46. When contact I42 engages I44 a circuit is closed which includes-the control motor I66 and the battery I52. Closing of this circuit initiates operation of the motor.

The motor drives a shaft diagrammatically represented by the dotted lines I54, I56, and I66, The shaft I66 carries a resetting pawl I66 which cams the contact I42 out of engagement with the contact I after the shaft has made one half of a revolution. Opening the contacts I44 and I42 stops the motor I 56. After the resetting pawl I42 downwardly, the contact I42 is engaged by the pawl I62 carried by the armature I46 and is held out of en-' gagement. The one-half revolution of the shaft I56 causes the movable contact arm I62 to move' out of engagement with the contact I66 and into engagement with the contact I64.

Once during each one-half revolution of the shaft I56, the movable contact I66 which is carried by the shaft I56 sweeps one contact seg ment I66 with the result that a circuit is closed from the main line I26, through the conductor IIII, motors III, I68, contact I66, and the main line I66. The motors I'II, I12 and I16 are the motors which automatically operate the butterfly dampers 66, 66 and 66 respectively. When current flows through line I66 the damper motors operate in one direction, and when current flows through line I II the damper motors operate in the re--- verse direction. the operation of the motor I56, the shaft I54 has also caused the operating rod I16 to have moved downwardly sufllciently so as to have rotated all of the threeway valves from the winter position to the summer position. The rod "6 cooperates with a plurality of operators "6 for the various valves, the arrangement being such that half a revolution of the shaft I 54 turns of a turn. The rod I16 carries on its upper end a movable contact bridging member I66 which engages contacts I66 and'I 62 during winter operating conditions and engages contacts I64 and I66during summer operating conditions.

In cha ging over from contact I26 moves into engagement with the contact I22 with the result that a circuit is closed from the main line I26 through the contacts I26 and I22, the contact I64, movable contact I62. solenoid I66 to the main. line I66. Energization of the solenoid I66 trips the movable contact arm I42 so that the motor circuit is again closed with the result that the valves etc., will be set for heating the room. After the motor I66 has made the necessary shift over, the resetting cam I66 again cams the movable contact I46 into the latched position.

Referring now to Fig. 4, it will be noted that the psychrometric device III comprises a main support 266 of insulationwhich carries on its I12 and I16, contact segment summer to winter the.

I izontal movement. A

being provided for controlling the system during summer conditions and vided for controlling the system during winter conditions. The support 266 is mounted for horport to the left, and an outside psychrometric device 226 biases the support to the right.

The movable contact I26 is pivotally mounted on a stationary pivot 222. The movable contact -otal movement to the arm 224 of the outside psychrometric. device 226. Directly above the device 226 there is provided a stationary pivot 266 on which is pivotally mounted a lever 262. The arrangement is such that pivotal movement of the arm 224 causes pivotal movement of the lever 262. As the outdoor effective temperature decreases the arm 224 tends to move to theleft, and as the outside eifective temperature increases the am 224 tends to move to the right.

Pull rods 264 and 266' connect the movable support.266 to the arms 224 and 262 respectively. The arrangement is such that when the outdoor temperature exceeds a predetermined high the lever 224, through the pull rod 234, will shift the support 266 to the right in accordance with the increase in temperature; and perature reaches a predetermined low the lever 262, through the pull rod 266 will, likewise, shift the movable support 266 to the right. The effect of the movement of the support 266 to the right, during winter operating conditions, is to increase the capacity of the heating equipment so as to each valve one quarter through a solenoid 244.

compensate for the colder walls. etc. Under summer conditions, the efl'ect of movement of the support 266 to the right will be to maintain the inside effective temperature slightly higher with the result that the change noticed when one leaves or enters the room will not b much greater at higher temperatures than at lower temperatures. Still referring to Fig. 4 which shows the circuit under winter conditions, it movable contact I26 will be noted that the is in engagement with a contact 266 which is in circuit with the solenoid valve 54 which controlsthe by-pass of refrigerant around the thermostatic expansion valve 50; The movable contact I 26 is also in engagement with a contact segment 242 which closes a circuit Energization of the solenoid 244 clOSes the switch 246 which completes a circuit from the main line 246 to the ignition system 246 of the internal combustion engine and the starter 266. a

The arrangement is such that when the engine starts and attains a predetermined speed, the speed responsive switch 252 opens the circuit through the starter mechanism 256 and closes this circuit through the solenoid valve 254 which automatically turns on the supply of cooling fluid for' the engine and compressing cooling jackets. In order to be able to increase the enginespeed asthe load on the conditioning apparatus increases, the main control switch is provided with face two sets of contact members-the one set 75 a shorter contact segment, 256 so'that, as the movable contact I26 moves into engagement with the segment 256, a circuit will be closed through the solenoid 266 which controls the engine throttle with the result that the speed of the engine will be increased. i

Still further movement of the movable contact the other set being prospring 262 biases the supwhen the tem- I in response to a further decrease in the temperature will cause the contact I20 to engage a stationary contact 260 which closes a circuit through a solenoid 262 which is instrumental in still further increasing the speed of the internal combustion engine. As the temperature within the room increases, the contact I20 will start moving to the right with the result that as it leaves the contact 260 the speed of the engine will be reduced, and as it leaves the contact segment 256 the speed of the engine will be further re duced, and as the movable contact leaves the contact segments 238 and 240 the ignition for the engine will be turned off, the cooling water will be shut off at 254 and the valve 54 will be closed.

'If the temperature within th room continues to increase to such an extent that cooling becomes necessary, the contact arm I20 will move into engagement with the contact I24 with the result that the equipment will be reset for cool-'- ing purposes as explained hereinabove. The arrangement is such that when the contact I20 engages the contact I24 it also engages the contact segment 264 which closes a circuit through the solenoid valve 266 which turns on the cooling Water for the condenser 24. The arm I20 simultaneously engages with another contact segment 268 which closes a circuit through the solenoid 244 for operating the switch 246 which starts the conditioning apparatus into operation. Contacts 210 and 212 corresponding to contacts 256 and 260 have been provided for increasing the speed of the engine as the conditioning load increases due to further rise in temperature.

In order to provide 'for humidity control a humidistat 214 has been provided which is in series circuit relationship with the valve 218 which turns on the water to the spray head II8 when the humidity becomes too low. The humidistat 2I4 and solenoid valve 216 are in series with the contacts I80, I90, and I92 with the result that the valve 216 will always remain closed during summer operating conditions due to the fact that the contact I80 will be out of engagement with the contacts I90 and I92 during summer operating conditions.

There may be times when the effective temperature within the enclosure may be satisfactory but the relative humidity may be excessively high. Under these conditions the humidistat 280 will close the circuit leading from the main line 240 through the solenoid 282 to the main line 239.

tion as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In combination, a reversible refrigerating system, an internal combustion engine drive for said system, indoor temperature responsive means for increasing the speed of said engine as the temperature goes either above or below a predetermined range, and means responsive'to the outdoor temperature modifying the action of said indoor temperature responsive means so as to raise said temperature range as the outdoor temperature either decreases or increases beyond a predetermined value.

2. In combination, a refrigerant condensing means in thermal exchange relationship with air to be conditioned, refrigerant evaporating means, refrigerant compressing means, refrigerant flow connections betweensaid condensing means, evaporating means and said compressing means, means for controlling the flow of refrig- Energization of the solenoid 282 starts up the cooling equipment but, at the same time that the solenoid 282 is energized, a branch circuit through the operating motor 284 is closed which automatically adjusts the three-way valve'12 so as to reheat the air leaving the heat exchange coil I2. In order to prevent reheating from taking place when the indoor temperature is high, a solenoid operated switch 286 has been provided In series with the humidity responsive device 280.

The solenoid operated switch 286 is biasedintothe closed position but is held open whenever the movable contact I20. is in engagement with the contact segment 210. The motor 83 which operates the fan 84 is connected directly across'the main lines 239 and 240 at all times so that the air will be circulated during all seasons of the year except at such times when the manually operated switch- 290 is open.- Opening of the switch 290, it will be observed, completely closes down the entire air conditioning system.

While the form of embodiment of the invenerant through said connections, an air heating coil in thermal exchange relationship with air to be conditioned, compressor operating means, means for flowing a, heat transfer medium in thermal exchange relationship with said compressor operating means, means for thereafter flowing said medium through said air heating coil, and means for flowing the heat transfer medium leaving said air heating coil into thermal exchange relationship with said evaporating means.

3. In combination, a refrigerant condensing means in thermal exchange relationship with air to be conditioned, refrigerant evaporating means, refrigerant compressing means, refrigerant flow connections between said condensing means, evaporating means-and said compressing means,

means for controlling the flow of refrigerant through said connections, an air heating coil in thermal exchange relationship with air to be conditioned, compressor operating means, means for flowing a heat transfer medium in thermal exchange relationship with said compressor operating means, means for thereafter flowing said medium through said air heating coil, means for flowing the heat transfer medium leaving said air heating coil into thermal exchange relationship with said evaporating means, and means for increasing the load on said compressor operating means in responseto an increase in the heating requirements.

4. Conditioning apparatus for an enclosure comprising in combination, a first heat exchange unit in thermal exchange relationship with a, medium to be attemperated, a compressor, an internal combustion engine for operating said compressor, a second heat exchange unit in fluid flow relationship with said first unit and said compressor, temperature responsive means for increasing the speed of said engine in response to a decrease in temperature, and means using waste heat from said internal combustion engine for heating said medium and for thereafter heating said second heat exchange unit.

5. In combination, a refrigerant condensing unit in thermal exchange relationship with air to be heated, a compressor, a heat exchange unit in fluid flow relationship with said refrigerant condensing unit and said compressor, an auxiliary heat exchange unit, means for reversing the functions of said condensing unit and said first named heat exchange unit, means for connecting said auxiliary heat exchange unit in series refrigerant flow relationship with said compressor, said condensing unit and said heat exchange unit in response to changes in temperature of said air, compressor operating means, and means utilizing waste heat generated by said compressor operating means for heating said auxiliary heat exchange unit.

6. In combination, a reversible refrigerating system including a compressor, indoor tempera- 10 termined value. 7

ROBERT R. CANDOR. 

